Double rotary fluid pump



Oct. 12, 1954 w. J. CONI-:RY

DOUBLE ROTARY FLUID PUMP 4 Sheets-Sheet l F'iled Sept. 7, 1948 ATTORNEYS Oct. 12, 1954 w, CQNERY 2,691,346.

. DOUBLE ROTARY FLUID PUMP Filed sept. 7, 1948 4 sheets-sheet 2 PIECE Q sa IFEA so 6 inve-Nwe 5 WILLIAM .L coNsnv sz BY *J..'./ am

A TTORNE YS Oct. 12, 1954 w J. coNERY DOUBLE ROTARY FLUID PUMP 4 Sheets-Sheet 5 Filed Sept. 7. 1948 Oct. l, 1954 w. J. coNERY DOUBLE ROTARY FLUID PUMP 4'Sheets-Sheet 4 Filed Sept. 7, 1948 luvfNroR WILLIAM J. CONERY fir-renueva Patented Oct. 12, 195.4

UNITED STATES anni TENT OFFICE DOUBLE ROTARY FLUID PUMP poration of Ohio Application September 7, 1948, Serial No. 47,985

(Cl. S- 5) 1 Claim. 1

This invention relates to pumps, and is concerned primarily with a pump designed for deep Well operation.

At the present time the arrangement of raising water from a Welland delivering it to a pressure tank in a dwelling or other building has followed certain more or less standardized lines.

Thus, it is common practice to employ a jet which is located at or beneath the well level and which is included as a part of a jet system. This jet entrains water from a Well and delivers it through a pump into an air separation chamber. From the air separation chamber water and air are pumped under pressure to the pressure tank.

There have been proposed so-called double or dual pump arrangements. Such arrangements generally follow the pattern of providing a jet supply pump for a jet system and a discharge pump for `delivering the water under pressure to the tank. Both of these pumps are usually driven from a power source such as an electric motor.

Heretofore it has been the practice to employ centrifugal impellers as the pumps and particularly use such an impeller on the discharge side. Many disadvantages attend the use of such a centrifugal impeller, and these disadvantages are intended to be greatly minimized, if not completely eliminated, by the present invention, which has, as its foremost objective the provision of a double rotary pump of the type indicated which includes a positive displacement pump on the discharge side.

With a positive displacement pump on the discharge side, it is possible to constantly pump air and water to the pressure chamber. Thus, there is definite assurance that there is always sumcient air in the storage tank to supply the water under the volume required for its service dispensing.

In this connection it is noted that another highly important object is the provision in a pump of the type indicated of an air separation chamber on the suction side which has an air inlet communicating with atmosphere together with the positive displacement pump on the discharge side.

With such an arrangement assurance is had that there is always sulcient air in the chamber to be pumped together with the water and delivered to the pump on the discharge side. With an adequate supply of air present at all times in the chamber the latter functions as a cushion and holds noise down to a minimum. Moreover, it eliminates any tendency of the positive dis- 2 placement pump on the discharge side from drawing more water than it should from the jet system, which would cause hammering and chattering.

In a pump of the type with which this invention is concerned it is common practice to provide an air separation chamber. As the name implies the chamber is provided for the purpose ci separating air from the water, as it is desirable tliat only water go back to the jet system.

In the co-pending application of William J. Conery, issued on July l5, 1952 as U. S. Patent 2,603,157 there is illustrated and described a pump of this type in which the air separation chamber is located on the suction side of both the jet and discharge pumps. 'This arrangement provides good separating action which is further enhanced by locating the discharge port from the air separation chamber at the uppermost level of the chamber.

The present invention has as a further object the provision of such an arrangement in combination with positive displacement pumps both on the jet supply and discharge sides.

When the positive displacement pumps are so included many decided advantages are achieved. In the first place high efficiency may be obtained for low capacity operations as compared to such operations when carried out with centrifugal impellers. This high eiilciency may be attributed to the fact that with the positive Adisplacement pumps the system may be operated at very high pressures, which permits the use of small bore tubing, thus reducing the size and cost of installations and also operating losses due to friction. Moreover, the power performance requirement of the motor depends on the pressure on the discharge side. If the system be for small capacities, then a relatively small motor may be used.

Another advantage of employing positive displacement pumps as above indicated is that the system will remain in operation even though leaks should develop in the jet system. This is denitely not true when a centrifugal impeller pump of the conventional single pump system is used as the jet supply pump and with a positive displacement pump at this point, the efficiency of operation is only slightly impaired with the pump remaining in substantially full operation.

Another advantage in employing the arrangement of air separating chamber above referred to in connection with the co-pending application, together with the positive displacement pump, is that no air is delivered in the jet system going to the Well. Air in the jet system is an undesirable factor which is definitely to be avoided as it reduces the eiiciency of operation, and this end is attained by this arrangement. Moreover, any gas which is in the Well is accommodated because it is separated from the water in the air separation chamber. Thus, when a double rotary jet pump includes this arrangement of the air separation chamber, together with the positive displacement pumps, it will function regardless of any well conditions, such as falling on' of the level of water, the subsequent restoration, and the like.

As above explained, one of the big advantages of employing a positive displacement pump on the discharge side is that it provides for a constant delivery capacity to the pressure tank at all pressures. This is not possible of achievement with a centrifugal impeller, and with this constant delivery there is assurance that the j et efhciency will remain constant and unimpaired, because the condition will never be created in which the water necessary to Operate the iet Supply System is drawn therefrom, that.. is, the iet supply System is never deprived of any of the water necessary for its operation. This is particularly true in View of the fact that the jet supply pump is at all times completely nooded.

A double rotary pump including the arrangement for the air separation chamber as above indicated, together With the positive displacement pumps, is particularly adapted for deep well use, and when so used there is, no need for any control valve, either manual or automatic. The pump is adapted for use with the jet located at any depth without necessitating any pressure regulating valve. This is true because the jet supply pump is always flooded- While the objects of the present invention may be achieved by employing any type of positive displacement pumps the invention has particularly in mind the use of the s o-called Moineau pump, which is a gear type of pump that is fully illustrated and described in the patent to Moineau 2,028,407 of January 2,1, 1936. Such a pump is particularly adapted for use when both the jet and discharge sides of a double rotary pump are arranged as contemplated by this invention.

Various other more detailed objects and advantages of the invention, such as arise in connection with carrying out the above noted ideas in a practical embodiment, will in part become apparent and in part be hereinafter stated as the description of the invention proceeds.

The invention, therefore, comprises a double rotary pump including a positive displacement pump on both the jet supply and discharge sides with an air separation chamber located on the suction side of both pumps and with the discharge therefrom located at the uppermost level thereof.

For a full and more complete understanding of the invention reference may be had to the following description and accompanying drawings wherein:

Figure 1 is av side view partly in section and partly in elevation and somewhat diagrammatic in nature showing a pump. designed in accordance with the precepts of this invention;

Figure 2 is a top plan view of the pump shown in Figure 1;

Figure 3 is a side View withy parts broken away and shown in section of one modication;

Figure 4 is an end elevation of the pump shown in Figure 3 with the base removed;

Figure 5 is a side View partly in elevation and partly in section of another modication; in which the positive displacement pumps are ofthe plunger type;

Figure 6 is a side view partly in elevation and partly in section of a modication in which there is a positive displacement pump on the discharge side only; and

Figure 7 is an end elevation of the pump shown in Figure 6.

Preferred embodiment Referring now to the drawings, and first more particularly to Figures 1 and 2, a preferred embodiment of the invention which is therein illustrated will be described.

Figure 1 embraces a representation of the essential elements of the entire system. Thus, the jet system is identiied in its entirety by the reference character J, the pump assembly at P, and the water tank at W.

The pump P is shown as supported by a base I0 which may take any form desired and which rests on a suitable supporting surface such as indicated at II. Supported by the base I0 is a casing I2 which houses an electric motor providing a motor drive shaft I3 that projects from opposite ends thereof.

Referring now more particularly to the left hand side of Figure 1, the motor drive shaft I3 is shown as journaled in a partition I4 by a bearing assembly I5'. The casing I2` has an end wall' I5 formed with a central opening through which the shaft I3 extends. An end casing member I1 is clamped on the end wall It in abutting relation with respect thereto in any preferred manner such as by the screw bolts shown at I8. This end casing I'l has an inner end Wall IS formed with an opening that aligns with the corresponding opening in the end wall i6 and through which the shaft I3 passes, A seal refer-red to as 20 serves to provide a fluid tight seal where the shaft I3 passes into the casing1 il. Seals of this type are old and well known and are available to thepublic as such. The particular type of seal employed is not a part of the invention and its details are therefore not herein described.

The casing Il has an outer end Wall 2l and a substantially vertical partition 22 which is spaced therefrom so as to dene an inlet chamber 23 andy a discharge chamber 2t. The casing Il is provided at the top with a. threaded port 25 which communicates with the discharge chamber 24 and into which is screwedthe threaded end of a conduit 25 that goes to the water tank W. A pressure operated automatic discharge valve 2'#v may be included in this conduit 2G at any convenient location and is provided for the purpose of relievingl pressure after it has reached a certain predetermined limit. The overflow through valve 2 is merely wasted into the atmosphere and the usual practice is to spill such overow into a drain.

The casing il is formed with a port 28 which communicates with the inlet chamber 23 and a pipe f2s has one end anchored in this port in a wel-1 known manner. The other end of the pipe 2S communicates with the, air separation clrlamn ber as will be later described.

The partition 22` has a central thickened portion which, as illustrated, is formed with a threaded bore tt that is substantially coaxial and in alignment with the motor shaft I3. A tubular sleeve 3l has one end threaded and screwed into the bore 3Q. This sleeve 3| carries a stator 32 of a Moineau pump which may consist of a rubber element, as illustrated, formed with helical passages therein.

rThe rotor of the Moineau pump is represented at 33 and is rotatable with-in the stator 32. This member 33 is relatively non-yielding and is drivably mounted on a shaft 34 which is, in turn, drivably connected to the motor shaft I3 as represented by the connection at 35.

It is evident that with the motor I3 rotating in the proper direction water is drawn from the inlet chamber 23 and affected by the Moineau pump comprising stator 32 and rotor 33, to be delivered to the discharge chamber 24 under increased pressure. Frorn the chamber 2A the water passes through port 25 and conduit 25 to the water tank W.

Referring now to the disclosure at the right hand side of Figure l it will be noted that the motor shaft I3 is journaled in bearings I5 corresponding to the similarly designated bearings at the other end. These bearings are carried by a partition 36 that is spaced inwardly from an end wall 31. An end casing 38 is clamped to this end wall 31 in abutting relation by the screw bolts I8. Another seal 2t is employed to seal the connection between the shaft I3 where it extends into the end casing 38.

The end casing 33 carries a partition structure 39 which defines an air separation chamber 4I! and a pressure chamber 4I. The casing 3S is formed with a port 42 which communicates with the pressure chamber 4| and in which is anchored a conduit 43 that constitutes the pressure supply side of the jet system J. The return side of the jet system is represented at 44 with the nozzle being shown at 45 and a venturi at 43. The casing 38 is formed with a port at 4l which communicates with the air separation chambe1 43 and in which is anchored the free end of the jet return 44. The casing 38 is also formed with another port 48 at substantially the uppermost level thereof and this port 48 communicates with the air separation chamber 4B at the top. The conduit 29 has one end anchored in the port 48.

The partition structure has a thickened part formed with a threaded bore 49 that is in coaxial alignment with the motor shaft I3. A sleeve 55 has one end screwed into this threaded bore 49 and extends into the pressure chamber 4I. The sleeve 5I! carries a stator 5| of a Moineau pump, while the rotor 52 of this pump is drivably carried by a shaft 53 which is drivably connected to the motor shaft I3 as shown at.54. This rotor 54 is rotatable within the stator 5l and serves to take water from the air separation chamber 48 and deliver it under increased pressure to the pressure chamber 4 I.

The end casing 38 is formed at the top with an opening in which is fitted an air inlet 55. The air inlet is included for the purpose of insuring an adequate supply of air for the air separation chamber and the pressure tank. A drain for the air separation chamber is shown as closed by a plug 56, while a drain for the pressure chamber 4I is shown as closed by a plug 51. Likewise, a drain for the discharge chamber 24 is shown as closed by a plug 58, and a drain for the inlet chamber 23 is shown as closed by a plug 59. It will be noted that the pressure chamber 4i is closed at its outer extremity by an end closure 60 which is secured in position on the end casing 38 by screw bolts shown at 6l.

Operation preferred embodiment In describing the operation of the apparatus depicted in Figures 1 and 2, it will be assumed that the electric motor drives the shaft I3 in the proper direction and at a required speed. As the shaft I3 rotates it drives the kMoineau pump made up of stator 5l and rotor 52, and it will. be remembered this is a positive displacementpump. This builds up pressure on waterv in the pressure chamber 4I and the water is thereby forced downwardly through port 42 and pipe 43 to the nozzle 45 of the jet system.

This nozzle 45 vwhich cooperates with the venturi 46 entrains water from the well and all of the water passes upwardly through the return pipe 4'4 from which it is admitted through port 41 into the air separation chamber 45. As much of this water as is required for the jet system will be drawn back by the Moineau pump and delivered to the pressure chamber 4I. However, the additional water which is entrained lfrom the well, together with air which has come either from the Well or from the inlet 55 is withdrawn from the port 48 and conducted through the conduit 23 to the inlet chamber 23 at the other end of the pump assembly P.

The Moineau pump comprising stator 32 and rotor 33 now takes water. from the inlet chamber 23 and delivers it under increased pressure to the discharge chamber 24. with air, is delivered from the latter to the water tank W through the port 25 and conduit 26.

The above described pump presents the following advantages:

(a) Air is constantly pumped by the positive displacement pump 32--33 on the discharge side and there is, therefore, definite assurance that there will always be sufficient air delivered to the tank W to maintain the required air supply there- 1n.

(b) There is always an adequate supply of air in the chamber 40 and this air acts as a cushion which holds noise down to a minimum.

(c) The pump will operate at high efficiency for low capacity operations as compared with centrifugal impellers. This may be attributed to the fact that the pump may be operated at high pressures to reduce friction losses and also the size of the pipe.

(d) The pump will remain in operation even though leaks should develop at any place in the jet system.

(e) The arrangement of the air separation chamber denitely eliminates any air in the jet system that goes to the well. Any gas in the well or other well conditions are denitely accommodated.

(f) The delivery to the tank W is constant forl all pressures which is not possible of achievement with a centrifugal impeller. Moreover, the jet eiiciency is constant due to the elimination of air therein.

(g) There is no need for any control valve in the jet supply system as it is effective at any depth.

(h) In the old single centrifugal impeller pump types the air and water from the jet pump must go through the impeller. This is not so in the present arrangement in which the air separation chamber is on the suction side of the jet supply pump.

All of these features add up to the fact that with the arrangement illustrated and described it is possible to provide a pump for deep well use which will operate at a high degree of efficiency.

First modz'flcatz'on y casing 61. The latter is provided at its lower end with an annular supporting ange 9 which The water, together aser-.aac

may be secured thereto in. any preferred manner as by Welding. A base 63 is formed Witha central opening 8. which receives the lower end of. the casingY 61 with the ange 9 restingA on the upper surface of the base 6-3 about the openingk 8'. Bolts 1 may be employed to anchor the iiange 9 to the base 63. Extending. vdownwardly from' one end of the motor is a motor shaft S that passes through an opening in an end Wall 66. Qlamped to this end wall 66 is the casing 61", the* anchorage being. effected by headed. screw bolts 'shown at 68;

The casing. 'scarries horizontal. partitions 69 and 'i0 and a. vertical partition 1t. These partitions denne a discharge chamber i2', an air separation chamber 3, andv a discharge chamber M. The casing. i is formed with a port 19 which. communicates with the' pressure chamber '14 and also with a conduit. 1S that extends to the pressure side of the jet system and also with the discharge chamber 12. The casing |51 is also formed With another port 'il that communicates with the air separation chamber 13a-.nd a pipe i8 that constitutes` the return side of the jet system. The casing El is formed with another port i5 which' communicates with the discharge chamber 'l and at which is anchored one endy of a conduit 8i! that goes to the Water tank..

The partition 69 has a thickened Wall structure formed with al threaded. bore- 3| that is in coaxial alignment with the motor shaft' 65'. A sleeve 82 has one end screwed intok the threaded bore at 3| and carries a stator 83` of a Moineau pump. The rotor for the Moineau pump is shown at Si and is drivably mounted on a reduced extension'v of ther shaft 65. The Moineau pump made up of the stator BSf and rotor. 84: serves to deliver Water pressure fromy the air separation chamber l to the discharge chamber 12.

The partition 'it is also formed Witha thickened Wall structure having a threaded bore 85`fin which. is anchored one end or" a sleeve l". The latter carries astator 85 of a Moineau. pump with the rotor of the pump which is indicated at 88 being mounted on theV shaft E5. The Moineau pump made up of stator 87 and rotor S3' delivers Water under increased pressure from the air separationv chamber i3 to the discharge chamber 74;

Operation Figures 3 and 4 As the shaft S5- isdriven by the motor S2 both the Moineau pumps are driven. The pump Btg-38 taiteswater from the air separat-ion chamber 'i3 and delivers it under increased pressure to the discharge chamber it. This forces Water out of the port T9 downwardly through the conduit 'i6 to the pressure side of the jet system in the Well. The jet of this system entrains water from the Well the combined water is passed upwardly through the return pipe 'lll and portil into the air separation chamber 13. As much Water as is needed to operate the jet system is again returned thereto by the pump B6--3. However, the surplus water which is that Water which has been entrained bythe jetlis'delivered by the pump SS-Bf'i to the discharge chamber 12. and from the latter through port 'I and conduit 3S to the Water tank.

Second modification Referring now more particularly to Figure 5, a modication involving. plunger type pumps will now be described.

Upstanding from a base' 819 is a pedestal 9|l which carries a housing 9| having oppositely directed conical ends. A shaft represented at 82 extends intothe housing 9| at al transverse axis and drivab'ly mounted on this shaft' is a pulley t".v A motor represented by broken lines at 94 is mounted Within. the base 8'9 and hasl a drive shaft 95 carrying a pulley 8E. lA drive belt 9'! extends over the pulleys @3 and Sii and serves to drive the shaft 82 from the motor 94.

Referring now more particularly to the left hand side of Figure 5, the end of the conical casing SH carries on the interior thereof a sleeve 98 in which is drivably mounted a crosshead 99. A pitman S00 establishes the driving relation between the shaft 92 and the crosshead 99.

Connected to the casi-ng si by a cylindrical section isla vertically ldisposed casing |02. This casing |02 has an internal partition construction comprising an upper horizontal partition it, vertical partition lilll, horizontal partition |135,V and lower horizontal partition HlS. Between the partitions |95l and |06 there is a supporting structure iii?! which supports a cylinder |63. Aplunger |853v is slidably mounted in the cylinder |88 and connected to the crosshead 99 by a rod im.

The top Wall of the casing m2 is formed with a threaded port i in Which is anchored a fitting H2. A conduit H3 connects this fitting H2 with the pressure side of the jet system in the well. The upper partition fles is formed with openings titl and HE. The partition |05 is formed with a port H6 which isin alignment with port Hit. A 'one-way valve Hl' controls communication through the port HB.

The partition ||l5 is also formed with another opening |4 i@ which is inalignment with the opening H5. A one-Way valve HS) controls communication through the opening HS. The partitions Mld and Hit together with the Walls of the casing denne pumping chambers |20 and |2|. Below the partit-ion 'it there is an inlet chamber |22. A Valve |23 provides communication between the chamber |522 and pumping chamber |2|, while another valve |24 provides communication between the chamber |22. and pumping chamber At this point it is Well to note that reciprocaticn of the plunger |88 will cause Water to be drawn fromthe inlet chamber |22 and alternately bev pumped through chambers |2|l and4 |'2-I through openings IIS and H8` to the port under increased pressure.

The bottom wall of. the casing |02 is formed with a threaded port |25 into which is screwed a tting |25. A conduit |21. is connected tothis fitting |26 and its other end is connected by a tting- |28. to a threaded port |29 for-med in a casing |30. The upper portion of the casingv |30 houses a plungerY type pump nriechanisrn which is exactly 4the saine as that described for lthe Aleft hand Apart of Figure 1. y l

lWithout referring to. allot the various elements ink detail, it isnoted that aY plunger. |3I reciprocates ina cylinder` |32 and is driven from the shaft 32 by a fpitman |33., crosshead |34 and rod |35. Reciprocation of this vpump alternately builds up .pressure in the pumping chambers |35 and |31.

The' top wall of the Icasing |343 is formed with a threaded vport |38 tofwhich is anchored a con-r duit |39 which goes to the Water tank. The lower. partition structure for the casing |39 is represented at |40 and this partition, 'together with the casing, dennes anair separation 'chamber 4 l. The casing- I is formed with a threaded l'port' |42' which communicates with the air separation chamber I|"l`-|"and` in which is anchored a tting |553; The return pipe of the jet vsystem is shown 49 at |44 and is connected to the tting |43. A baflie |45 is positioned in the air separation chamber |4| between the ports |42 and |29.

Operation Figure 5 As the shaft 92 is driven by the motor 94 the plunger type pumps at each side are driven through the pitmans and |33. As the pump at the left hand side of Figure is operated water is drawn from the inlet chamber |22 and alternately passed upwardly through the pumping chambers |20 and |2| through openings ||6 and ||8 to the port at the top under increased pressure. The water is thereby forced vthrough the conduit ||3 down to the pressure side of the jet system in the well. The jet of this system entrains additional water from the well and the combined water passes upwardly through conduit |44 to the air separation chamber |4|. From the latter sufficient water is drawn through port |29 and conduit |21 to operate the jet system. The remainder of the Water is pumped by the plunger |3| alternately through chambers |36 and |31 yto the port |38 from whence it passes through conduit |39 to the water tank.

Third modification Referring to Figures 6 and 7, a motor casing is shown at' |46 as being supported by a base |41. Mounted within the casing is a motor |48 from which projects at opposite sides a motor shaft |49. Mounted on the left hand side of the casing |46 is an end casing |50 having a partition |5| which defines an inlet chamber |52 and a discharge chamber |53. The casing |50 is formed with a port |54 which communicates with the discharge chamber |53 and in which is anchored one end of a conduit |55 that goes to a water tank. The end of the casing |50V is also formed with a port |56 which communicates with the inlet chamber |52 and to which is anchored one end of a conduit |51. The partition |5| has anchored therein one end of a sleeve |58 and this sleeve |58 carries a stator |59 of a Moineau pump. The rotor of this pump is shown at |60 and is drivably mounted on one end of the shaft 49. At the other end of the casing |46 there is mounted an end casing |6| having a partition 62 which denes a pressure chamber |63 and an air separation chamber |64. formed with a port |65 which communicates with the pressure chamber |63 and with a conduit |66 going to the pressure side of the jet system. The casing |6| is also formed with another port |61 that communicates with the air separation chamber |64 and with a conduit |68 on the return side of the jet system. 'I'he casing |6| at the top is formed with a port |69 that communicates with the air separation chamber |64 and the pipe |51 has one end anchored in this port |69.

A centrifugal impeller is represented at and is shown as being drivably mounted on the shaft |49. The mpeller |1||- has a suction port at |1| Which communicates with the air separation chamber |64 while the passages |12 communicate between the impeller |10 and the pressure chamber |63.

of the shaft |49. The centrifugal impeller |10 d draws water from the air separation chamber |64 and delivers it under increased pressure to the pressure chamber |63. From the latter the Water is forced through port |65 to the pressure side of the jet system. The jet in this system entrains water in the well and the combined water is returned through the conduit |68 and the port |61 to the. air separation chamber |64. As much water as is needed for the jet supply system is returned to the impeller |10 through the suction port |1|. However, the additional water which has been entrained by the jet is drawn out through port |69 and passes through conduit |51 and port |56 to the inlet chamber |52. The Moineau pump 59| 60 delivers water from the inlet chamber |52 to the discharge chamber |53 under increased pressure. This water is passed through port |54 and conduit |55 to the water tank.

It is evident that the form of invention shown in Figures 6 and 7 denotes that a positive displacement pump of the Moineau type is on the discharge side only. However, definite advantages attach to this arrangement in that there is constant delivery to the water tank for all pressures.

While preferred embodiments of the invention are hereinbefore set forth, it will be clearly understood that the invention is not to be limited to the exact apparatus, devices and mechanisms illustrated and described, because various modications of these details may be provided in putting the invention into practice within the purview of the appended claim.

I claim:

A pumping system comprising in combination, a pair of pumps each having a suction inlet and a discharge outlet, said pumps consisting of rotary positive displacement pumps of the Moineau type, drive shafts for actuating said pumps, said drive shafts being mounted on a common axis, means for driving said shafts, a casing defining therein an air separation chamber, said chamber being in communication with said inlets, an air inlet in the upper portion of said air chamber, a jet pump having a nozzle and a diffuser, a conduit extending from the inlet side of the nozzle to the discharge outlet of one of said pumps, a conduit extending from the discharge side of the diffuser to said air separation chamber which is common to each of said pumps, and a discharge pipe to service extending from the discharge outlet of the pump other than the pump to which the nozzle of the jet pump is connected.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 517,229 Nevill Mar. 27, 1894 1,438,008 Young Dec. 5, 1922 1,910,707 Mohr May 23, 1933 2,028,407 Moineau Jan. 21, 1936 2,196,453 Horvath Apr. 9, 1940 2,354,811 Jacuzzi Aug. l, 1944 2,466,792 Conery Apr. 20, 1949 2,603,157 Conery July 15, 1952 FOREIGN PATENTS Number Country Date 206,674 Germany 1909 382,592 Great Britain 1932 

